Publications
Clean Hydrogen Roadmap: Is Greater Realism Leading to more Credible Paths Forward?
Sep 2023
Publication
"The Oxford Institute for Energy Studies started researching the role of hydrogen in the energy transition in 2020. Since then the interest in hydrogen has continued to grow globally across the energy industry. A key research question has been the extent to which clean hydrogen can be scaled up at reasonable cost and whether it can play a significant role in the global energy system. In April 2022 OIES launched a new Hydrogen Research Programme under the overarching theme of ’building business cases for a hydrogen economy’. This overarching theme was selected based on the observation that most clean hydrogen developments to date had been relatively small-scale pilot or demonstration projects typically funded by government grants or subsidies. For clean hydrogen to play a significant role there will need to be business cases developed in order to attract the many hundreds of billions of dollars of investment required most of which will need to come from the private sector albeit ultimately underpinned by government-backed decarbonisation policies. Just over a year has passed since the start of the Hydrogen Research Programme and the intention of this paper is to pull together key themes which have emerged from the research so far and which can form a useful framework for further research both by OIES and others.<br/>The six key themes in this paper listed below are intended to create a framework to at least start to address the challenges:<br/>Hydrogen is in competition with other decarbonisation alternatives.<br/>The business case for clean hydrogen relies on government policy to drive decarbonisation.<br/>It is essential to understand emissions associated with potential hydrogen investments.<br/>Hydrogen investments need to consider the full value chain and its geopolitics.<br/>Transport of hydrogen is expensive and so should be minimised.<br/>Storage of hydrogen is an essential part of the value chain and requires more focus.
Two-stage Optimization of Hydrogen and Storage Coordination for a Multi-region Flexible Intermodal Multi-energy Port System
Jan 2024
Publication
To address the issue of imbalanced electricity and hydrogen supply and demand in the flexible multi-energy port area system a multi-regional operational optimization and energy storage capacity allocation strategy considering the working status of flexible multi-status switches is proposed. Firstly based on the characteristics of the port area system models for system operating costs generation equipment energy storage devices flexible multi-status switches and others are established. Secondly the system is subjected to a first-stage optimization where different regions are optimized individually. The working periods of flexible multi-status switches are determined based on the results of this first-stage optimization targeting the minimization of the overall daily operating costs while ensuring 100% integration of renewable energy in periods with electricity supply-demand imbalances. Subsequently additional constraints are imposed based on the results of the first-stage optimization to optimize the entire system obtaining power allocation during system operation as well as power and capacity requirements for energy storage devices and flexible multi-status switches. Finally the proposed approach is validated through simulation examples demonstrating its advantages in terms of economic efficiency reduced power and capacity requirements for energy storage devices and carbon reduction.
Look-ahead Scheduling of Energy-Water Nexus Integrated with Power2X Conversion Technologies under Multiple Uncertainties
Aug 2023
Publication
Co-optimizing energy and water resources in a microgrid can increase efficiency and improve economic performance. Energy-water storage (EWS) devices are crucial components of a high-efficient energy-water microgrid (EWMG). The state of charge (SoC) at the end of the first day of operation is one of the most significant variables in EWS devices since it is used as a parameter to indicate the starting SoC for the second day which influences the operating cost for the second day. Hence this paper examines the benefits and applicability of a lookahead optimization strategy for an EWMG integrated with multi-type energy conversion technologies and multienergy demand response to supply various energy-water demands related to electric/hydrogen vehicles and commercial/residential buildings with the lowest cost for two consecutive days. In addition a hybrid info-gap/robust optimization technique is applied to cover uncertainties in photovoltaic power and electricity prices as a tri-level optimization framework without generating scenarios and using the probability distribution functions. Duality theory is also used to convert the problem into a single-level MILP so that it can be solved by CPLEX. According to the findings the implemented energy-water storage systems and look-ahead strategy accounted for respectively 4.03% and 0.43% reduction in the total cost.
Capacity Configuration Optimization for Green Hydrogen Generation by Solar-wind Hybrid Power Based on Comprehensive Performance Criteria
Aug 2023
Publication
Green hydrogen generation driven by solar-wind hybrid power is a key strategy for obtaining the low-carbon energy while by considering the fluctuation natures of solar-wind energy resource the system capacity configuration of power generation hydrogen production and essential storage devices need to be comprehensively optimized. In this work a solar-wind hybrid green hydrogen production system is developed by combining the hydrogen storage equipment with the power grid the coordinated operation strategy of solar-wind hybrid hydrogen production is proposed furthermore the NSGA-III algorithm is used to optimize the system capacity configuration with the comprehensive performance criteria of economy environment and energy efficiency. Through the implemented case study with the hydrogen production capacity of 20000 tons/year the abandoned energy power rate will be reduced to 3.32% with the electrolytic cell average load factor of 64.77% and the system achieves the remarkable carbon emission reduction. In addition with the advantage of connect to the power grid the generated surplus solar/wind power can be readily transmitted with addition income when the sale price of produced hydrogen is suggested to 27.80 CNY/kgH2 the internal rate of return of the system reaches to 8% which present the reasonable economic potential. The research provides technical and methodological suggestions and guidance for the development of solar-wind hybrid hydrogen production schemes with favorable comprehensive performance.
Prospective Assessment of Transformation Pathways Toward Low-carbon Steelmaking: Evaluating Economic and Climate Impacts in Germany
Jan 2024
Publication
Due to climate change there is an urgent need to decarbonize high-emission industries. As coal-based operations predominate in primary steelmaking the steel industry offers an exceptionally high potential for reducing greenhouse gas emissions. Alternative processes for almost fully decarbonized primary steelmaking exist but require substantial investments by steelmakers for their implementation while maintaining desired production levels during the transformation periods. In this context the energy carriers required change such that the transformation of the steelmaking processes is deeply intertwined with the transformation of the background system. For the first time we evaluate potential transformation pathways from the steelmakers’ perspective using a prospective life cycle assessment approach. We find that hydrogen may facilitate a reduction of direct emissions by around 96 % compared to conventional steelmaking in 2050. However indirect emissions remain at a high level throughout the transformation period unless the upstream stages of the value chain are transformed accordingly.
Global Land and Water Limits to Electrolytic Hydrogen Production Using Wind and Solar Resources
Sep 2023
Publication
Proposals for achieving net-zero emissions by 2050 include scaling-up electrolytic hydrogen production however this poses technical economic and environmental challenges. One such challenge is for policymakers to ensure a sustainable future for the environment including freshwater and land resources while facilitating low-carbon hydrogen production using renewable wind and solar energy. We establish a country-by-country reference scenario for hydrogen demand in 2050 and compare it with land and water availability. Our analysis highlights countries that will be constrained by domestic natural resources to achieve electrolytic hydrogen self-sufficiency in a net-zero target. Depending on land allocation for the installation of solar panels or wind turbines less than 50% of hydrogen demand in 2050 could be met through a local production without land or water scarcity. Our findings identify potential importers and exporters of hydrogen or conversely exporters or importers of industries that would rely on electrolytic hydrogen. The abundance of land and water resources in Southern and Central-East Africa West Africa South America Canada and Australia make these countries potential leaders in hydrogen export.
Large Eddy Simulations of a Hydrogen-Air Explosion in an Obstructed Chamber Using Adaptive Mesh Refinement
Sep 2023
Publication
Following the growing use of hydrogen in the industry gas explosions have become a critical safety issue. Computational Fluid Dynamic (CFD) and in particular the Large Eddy Simulation (LES) approach have already shown their great potential to reproduce such scenarios with high fidelity. However the computational cost of this approach is an obvious limiting factor since fine grid resolutions are often required in the whole computational domain to ensure a correct numerical resolution of the deflagration front all along its propagation. In this context Adaptive Mesh Refinement (AMR) is of great interest to reduce the computational cost as it allows to dynamically refine the mesh throughout the explosion scenario only in regions where Quantities of Interest (QoI) are detected. This study aims to demonstrate the strong potential of AMR for the LES of explosions. The target scenario is a hydrogen-air explosion in the GraVent explosion channel [1]. Using the massively parallel Navier- Stokes compressible solver AVBP a reference simulation is first obtained on a uniform and static unstructured mesh. The comparison with the experiments shows a good agreement in terms of absolute flame front speed overpressure and flow visualisation. Then an AMR simulation is performed targeting the same resolution as the reference simulation only in regions where QoI are detected i.e. inside the reaction zones and vortical structures. Results show that the accuracy of the reference simulation is recovered with AMR for only 12% of its computational cost.
Risk Sensitivity Study as the Basis for Risk-informed Consequence-based Setback Distances for Liquid Hydrogen Storage Systems
Sep 2023
Publication
A quantitative risk assessment on a representative liquid hydrogen storage system was performed to identify the main drivers of individual risk and provide a technical basis for revised separation distances for bulk liquid hydrogen storage systems in regulations codes and standards requirements. The framework in the Hydrogen Plus Other Alternative Fuels Risk Assessment Models (HyRAM+) toolkit was used and multiple relevant inputs to the risk assessment (e.g. system pipe size ignition probabilities) were individually varied. For each set of risk assessment inputs the individual risk as a function of the distance away from the release point was determined and the risk-based separation distance was determined from an acceptable risk criterion. These risk-based distances were then converted to equivalent leak size using consequence models that would result in the same distance to selected hazard criteria (i.e. extent of flammable cloud heat flux and peak overpressure). The leak sizes were normalized to a fraction of the flow area of the source piping. The resulting equivalent fractional hole sizes for each sensitivity case were then used to inform selection of a conservative fractional flow area leak size of 5% that serves as the basis for consequence-based separation distance calculations. This work demonstrates a method for using a quantitative risk assessment sensitivity study to inform the selection of a basis for determining consequence-based separation distances.
A Systematic Review of Predictive, Optimization, and Smart Control Strategies for Hydrogen-based Building Heating Systems
Nov 2024
Publication
The use of energy in the built environment contributes to over one-third of the world’s carbon emissions. To reduce that effect two primary solutions can be adopted i.e. (i) renovation of old buildings and (ii) increasing the renewable energy penetration. This review paper focuses on the latter. Renewable energy sources typically have an intermittent nature. In other words it is not guaranteed that these sources can be harnessed on demand. Thus complement solutions should be considered to use renewable energy sources efficiently. Hydrogen is recognized as a potential solution. It can be used to store excess energy or be directly exploited to generate thermal energy. Throughout this review various research papers focusing on hydrogen-based heating systems were reviewed analyzed and classified from different perspectives. Subsequently articles related to machine learning models optimization algorithms and smart control systems along with their applications in building energy management were reviewed to outline their potential contributions to reducing energy use lowering carbon emissions and improving thermal comfort for occupants. Furthermore research gaps in the use of these smart strategies in residential hydrogen heating systems were thoroughly identified and discussed. The presented findings indicate that the semi-decentralized hydrogen-based heating systems hold significant potential. First these systems can control the thermal demand of neighboring homes through local substations; second they can reduce reliance on power and gas grids. Furthermore the model predictive control and reinforcement learning approaches outperform other control systems ensuring energy comfort and cost-effective energy bills for residential buildings.
Towards the Simulation of Hydrogen Leakage Scenarios in Closed Buildings Using ContainmentFOAM
Sep 2023
Publication
The increase of using hydrogen as a replacement for fossil fuels in power generation and mobility is expected to witness a huge leap in the next decades. However several safety issues arise due to the physical and chemical properties of hydrogen especially its wide range of flammability. In case of Hydrogen leakage in confined areas Hydrogen clouds can accumulate in the space and their concentration can build up quickly to reach the lower flammability limit (LFL) in case of not applying a proper ventilation system. As a part of the Living Lab Energy Campus (LLEC) project at Jülich Research Centre the use of hydrogen mixed with natural gas as a fuel for the central heating system of the campus is being studied. The current research aims to investigate the release dispersion and formation and the spread of a hydrogen cloud inside the central utility building at the campus of Jülich Research Centre in case of hypothetical accidental leakage. Such a leakage is simulated using the opensource containmentFoam package base on OpenFOAM CFD code to numerically simulate the behavior of the air-hydrogen mixture. The critical locations where hydrogen concentrations can reach the LFL values are shown.
Energy Management of Hydrogen Hybrid Electric Vehicles - A Potential Analysis
Jan 2024
Publication
The hydrogen combustion engine (H2 ICE) is known to be able to burn H2 producing no CO2 emissions and extremely low engine-out NOeo emissions. In this work the potential to reduce the NOeo emissions through the implementation of electric hybridization of an H2 ICE-equipped passenger car (H2 -HEV) combined with a dedicated energy management system (EMS) is discussed. Achieving a low H2 consumption and low NOeo emissions are conflicting objectives the trade-off of which depends on the EMS and can be represented as a Pareto front. The dynamic programming algorithm is used to calculate the Pareto-optimal EMS calibrations for various driving missions. Through the utilization of a dedicated energy management calibration H2 -HEVs exhibit the potential to decrease the NOeo x emissions by more than 90% while decreasing the H2 consumption by over 16% compared to a comparable non-hybridized H2 -vehicle. The present paper represents the initial potential analysis suggesting that H2 -HEVs are a viable option towards a CO2 -free mobility with extremely low NOeo emissions.
The Heat Transfer Potential of Compressor Vanes on a Hydrogen Fueled Turbofan Engine
Sep 2023
Publication
Hydrogen is a promising fuel for future aviation due to its CO2-free combustion. In addition its excellent cooling properties as it is heated from cryogenic conditions to the appropriate combustion temperatures provides a multitude of opportunities. This paper investigates the heat transfer potential of stator surfaces in a modern high-speed low-pressure compressor by incorporating cooling channels within the stator vane surfaces where hydrogen is allowed to flow and cool the engine core air. Computational Fluid Dynamics simulations were carried out to assess the aerothermal performance of this cooled compressor and were compared to heat transfer correlations. A core air temperature drop of 9.5 K was observed for this cooling channel design while being relatively insensitive to the thermal conductivity of the vane and cooling channel wall thickness. The thermal resistance was dominated by the air-side convective heat transfer and more surface area on the air-side would therefore be required in order to increase overall heat flow. While good agreement with established heat transfer correlations was found for both turbulent and transitional flow the correlation for the transitional case yielded decent accuracy only as long as the flow remains attached and while transition was dominated by the bypass mode. A system level analysis indicated a limited but favorable impact at engine performance level amounting to a specific fuel consumption improvement of up to 0.8% in cruise and an estimated reduction of 3.6% in cruise NOx. The results clearly show that although it is possible to achieve high heat transfer rate per unit area in compressor vanes the impact on cycle performance is constrained by the limited available wetted area in the low-pressure compressor.
Subsurface Renewable Energy Storage Capcity for Hydrogen, Methane and Compress Air - A Performance Assessment Study from the North German Basin
Jul 2021
Publication
The transition to renewable energy sources to mitigate climate change will require large-scale energy storage to dampen the fluctuating availability of renewable sources and to ensure a stable energy supply. Energy storage in the geological subsurface can provide capacity and support the cycle times required. This study investigates hydrogen storage methane storage and compressed air energy storage in subsurface porous formations and quantifies potential storage capacities as well as storage rates on a site-specific basis. For part of the North German Basin used as the study area potential storage sites are identified employing a newly developed structural geological model. Energy storage capacities estimated from a volume-based approach are 6510 TWh and 24544 TWh for hydrogen and methane respectively. For a consistent comparison of storage capacities including compressed air energy storage the stored exergy is calculated as 6735 TWh 25795 TWh and 358 TWh for hydrogen methane and compressed air energy storage respectively. Evaluation of storage deliverability indicates that high deliverability rates are found mainly in two of the three storage formations considered. Even accounting for the uncertainty in geological parameters the storage potential for the three considered storage technologies is significantly larger than the predicted demand and suitable storage rates are achievable in all storage formations.
Hydrogen as an Energy Carrier—An Overview over Technology, Status, and Challenges in Germany
Dec 2024
Publication
Hydrogen is set to become an important energy carrier in Germany in the next decades in the country’s quest to reach the target of climate neutrality by 2045. To meet Germany’s potential green hydrogen demand of up to 587 to 1143 TWh by 2045 electrolyser capacities between 7 and 71 GW by 2030 and between 137 to 275 GW by 2050 are required. Presently the capacities for electrolysis are small (around 153 MW) and even with an increase in electrolysis capacity of >1 GW per year Germany will still need to import large quantities of hydrogen to meet its future demand. This work examines the expected green hydrogen demand in different sectors describes the available technologies and highlights the current situation and challenges that need to be addressed in the next years to reach Germany’s climate goals with regard to scaling up production infrastructure development and transport as well as developing the demand for green hydrogen.
Methanol, a Plugin Marine Fuel for Green House Gas Reduction—A Review
Jan 2024
Publication
The escalating global demand for goods transport via shipping has heightened energy consumption impacting worldwide health and the environment. To mitigate this international organizations aim to achieve complete fuel desulphurization and decarbonization by 50% by 2050. Investigating eco-friendly fuels is crucial particularly those with a reduced carbon and zero sulfur content. Methanol derived mainly from renewable sources and produced by carbon dioxide’s hydrogenation method stands out as an effective solution for GHG reduction. Leveraging its favorable properties global scalability and compatibility with the existing infrastructure especially LNGs methanol proves to be a cost-efficient and minimally disruptive alternative. This review explores methanol’s role as a hybrid maritime fuel emphasizing its ecological production methods advantages and challenges in the shipping industry’s green transition. It discusses the environmental impacts of methanol use and analyzes economic factors positioning methanol not only as an ecofriendly option but also as a financially prudent choice for global shipping. Methanol is efficient and cost-effective and excels over MGO especially in new ships. It is economically advantageous with decreasing investment costs compared to LNG while providing flexibility without specialized pressure tanks. Global marine fuel trends prioritize fuel traits accessibility and environmental considerations incorporating factors like policies emissions bunkering and engine adaptability during transitions.
Environmental Implications and Levelized Cost Analysis of E-fuel Production under Photovoltaic Energy, Direct Air Capture, and Hydrogen
Jan 2024
Publication
The ecological transition in the transport sector is a major challenge to tackle environmental pollution and European legislation will mandate zero-emission new cars from 2035. To reduce the impact of petrol and diesel vehicles much emphasis is being placed on the potential use of synthetic fuels including electrofuels (e-fuels). This research aims to examine a levelised cost (LCO) analysis of e-fuel production where the energy source is renewable. The energy used in the process is expected to come from a photovoltaic plant and the other steps required to produce e-fuel: direct air capture electrolysis and Fischer-Tropsch process. The results showed that the LCOe-fuel in the baseline scenario is around 3.1 €/l and this value is mainly influenced by the energy production component followed by the hydrogen one. Sensitivity scenario and risk analyses are also conducted to evaluate alternative scenarios and it emerges that in 84% of the cases LCOe-fuel ranges between 2.8 €/l and 3.4 €/l. The findings show that the current cost is not competitive with fossil fuels yet the development of e-fuels supports environmental protection. The concept of pragmatic sustainability incentive policies technology development industrial symbiosis economies of scale and learning economies can reduce this cost by supporting the decarbonisation of the transport sector.
Renewable Hydrogen Requirements and Impacts for Network Balancing: A Queensland Cae Study
Dec 2023
Publication
Hydrogen is the gas of the moment: an abundant element that can be created using renewable energy transported in gaseous or liquid form and offering the ability to provide energy with only water vapour as an emission. Hydrogen can also be used in a fuel blend in electricity generation gas turbines providing a low carbon option for providing the peak electricity to cover high demand and firming.<br/>While the electricity grid is itself transforming to decarbonising hard-to-abate industries such as cement and bauxite refineries are slower to reduce emissions constrained by their high temperature process requirements. Hydrogen offers a solution allowing onsite production process heat with waste heat recovery supporting blended gas turbine generation for onsite electricity supply.<br/>This article builds on decarbonisation pathway simulation results from an ANEM model of the electricity grid identifying the amount of peak demand energy required from gas turbines. The research then examines the quantity flow rate storage requirements and emissions reduction if this peak generation were supplied by open cycle hydrogen capable gas turbines.
Hydrogen Quality in Used Natual Gas Pipelines: An Experimental Investigation of Contaminants According to ISO 14687:2019 Standard
Sep 2023
Publication
The transport of hydrogen in used natural gas pipelines is a strategic key element of a pan-European hydrogen infrastructure. At the same time accurate knowledge of the hydrogen quality is essential in order to be able to address a wide application range. Therefore an experimental investigation was carried out to find out which contaminants enter into the hydrogen from the used natural gas pipelines. Pipeline elements from the high pressure gas grid of Austria were exposed to hydrogen. Steel pipelines built between 1960 and 2018 which were operated with odorised and pure natural gas were examined. The hydrogen was analysed according to requirements of ISO14687: 2019 Grade D measurement standard. The results show that based on age odorization and sediments different contimenants are introduced. Odorants hydrocarbons but also sulphur compounds ammonia and halogenated hydrogen compounds were identified. Sediments are identified as the main source of impurities. However the concentrations of the introduced contaminants were low (6 nmol/mol to 10 μmol/mol). Quality monitoring with a wide range of detection options for different components (sulphur halogenated compounds hydrocarbons ammonia and atmospheric components) is crucial for real operation. The authors deduce that a Grade A hydrogen quality can be safely achieved in real operation.
A Review on Hydrogen Embrittlement and Risk-based Inspection of Hydrogen Technologies
May 2023
Publication
Hydrogen could gradually replace fossil fuels mitigating the human impact on the environment. However equipment exposed to hydrogen is subjected to damaging effects due to H2 absorption and permeation through metals. Hence inspection activities are necessary to preserve the physical integrity of the containment systems and the risk-based (RBI) methodology is considered the most beneficial approach. This review aims to provide relevant information regarding hydrogen embrittlement its effect on materials’ properties and the synergistic interplay of the factors influencing its occurrence. Moreover an overview of predictive maintenance strategies is presented focusing on the RBI methodology. A systematic review was carried out to identify examples of the application of RBI to equipment exposed to hydrogenated environments and to identify the most active research groups. In conclusion a significant lack of knowledge has been highlighted along with difficulties in applying the RBI methodology for equipment operating in a pure hydrogen environment.
Up-to-Date Status of Geoscience in the Field of Natural Hydrogen with Consideration of Petroleum Issues
Sep 2023
Publication
The perspective of natural hydrogen as a clear carbon-free and renewable energy source appears very promising. There have been many studies reporting significant concentrations of natural hydrogen in different countries. However natural hydrogen is being extracted to generate electricity only in Mali. This issue originates from the fact that global attention has not been dedicated yet to the progression and promotion of the natural hydrogen field. Therefore being in the beginning stage natural hydrogen science needs further investigation especially in exploration techniques and exploitation technologies. The main incentive of this work is to analyze the latest advances and challenges pertinent to the natural hydrogen industry. The focus is on elaborating geological origins ground exposure types extraction techniques previous detections of natural hydrogen exploration methods and underground hydrogen storage (UHS). Thus the research strives to shed light on the current status of the natural hydrogen field chiefly from the geoscience perspective. The data collated in this review can be used as a useful reference for the scientists engineers and policymakers involved in this emerging renewable energy source.
A Computational Study of Hydrogen Dispersion and Explosion after Large-Scale Leakage of Liquid Hydrogen
Nov 2023
Publication
This study employs the FLACS code to analyze hydrogen leakage vapor dispersion and subsequent explosions. Utilizing pseudo-source models a liquid pool model and a hybrid model combining both we investigate dispersion processes for varying leak mass flow rates (0.225 kg/s and 0.73 kg/s) in a large open space. We also evaluate explosion hazards based on overpressure and impulse effects on humans. The computational results compared with experimental data demonstrated reasonable hydrogen vapor cloud concentration predictions especially aligned with the wind direction. For higher mass flow rate of 0.73 kg/s the pseudo-source model exhibited the most reasonable predictive performance for locations near the leak source despite the hybrid model yielded similar results to the pseudo-source model while the liquid pool model was more suitable for lower mass flow rate of 0.225 kg/s. Regarding explosion analyses using overpressure-impulse diagram higher mass flow rates leaded to potentially fatal overpressure and impulse effects on humans. However lower mass flow rates may cause severe eardrum damage at the maximum overpressure point.
Fuelling the Future: An In-depth Review of Recent Trends, Challenges and Opportunities of Hydrogen Fuel Cell for a Sustainable Hydrogen Economy
Sep 2023
Publication
Hydrogen has gained tremendous momentum worldwide as an energy carrier to transit to a net zero emission energy sector. It has been widely adopted as a promising large-scale renewable energy (RE) storage solution to overcome RE resources’ variability and intermittency nature. The fuel cell (FC) technology became in focus within the hydrogen energy landscape as a cost-effective pathway to utilize hydrogen for power generation. Therefore FC technologies’ research and development (R&D) expanded into many pathways such as cost reduction efficiency improvement fixed and mobile applications lifetime safety and regulations etc. Many publications and industrial reports about FC technologies and applications are available. This raised the necessity for a holistic review study to summarize the state-of-the-art range of FC stacks such as manufacturing the balance of plant types technologies applications and R&D opportunities. At the beginning the principal technologies to compare the well known types followed by the FC operating parameters are presented. Then the FC balance of the plant i.e. building components and materials with its functionality and purpose types and applications are critically reviewed with their limitations and improvement opportunities. Subsequently the electrical properties of FCs with their key features including advantages and disadvantages were investigated. Applications of FCs in different sectors are elaborated with their key characteristics current status and future R&D opportunities. Economic attributes of fuel cells with a pathway towards low cost are also presented. Finally this study identifies the research gaps and future avenues to guide researchers and the hydrogen industry.
Thermodynamic Analysis of the Combustion Process in Hydrogen-Fueled Engines with EGR
Jun 2024
Publication
This article presents a novel approach to the analysis of heat release in a hydrogen-fueled internal combustion spark-ignition engine with exhaust gas recirculation (EGR). It also discusses aspects of thermodynamic analysis common to modeling and empirical analysis. This new approach concerns a novel method of calculating the specific heat ratio (cp/cv) and takes into account the reduction in the number of moles during combustion which is characteristic of hydrogen combustion. This reduction in the number of moles was designated as a molar contraction. This is particularly crucial when calculating the average temperature during combustion. Subsequently the outcomes of experimental tests including the heat-release rate the initial combustion phase (denoted CA0- 10) and the main combustion phase (CA10-90) are presented. Furthermore the impact of exhaust gas recirculation on the combustion process in the engine is also discussed. The efficacy of the proposed measures was validated by analyzing the heat-release rate and calculating the mean combustion temperature in the engine. The application of EGR in the range 0-40% resulted in a notable prolongation of both the initial and main combustion phases which consequently influenced the mean combustion temperature.
Application of the Metalog Probability Distribution Family to Predict Energy Production by Photovoltaic Systems for the Purposes of Generating Green Hydrogen
Jul 2024
Publication
The article presents the application of the metalog family of probability distributions to predict the energy production of photovoltaic systems for the purpose of generating small amounts of green hydrogen in distributed systems. It can be used for transport purposes as well as to generate energy and heat for housing purposes. The monthly and daily amounts of energy produced by a photovoltaic system with a peak power of 6.15 kWp were analyzed using traditional statistical methods and the metalog probability distribution family. On this basis it is possible to calculate daily and monthly amounts of hydrogen produced with accuracy from the probability distribution. Probabilistic analysis of the instantaneous power generated by the photovoltaic system was used to determine the nominal power of the hydrogen electrolyzer. In order to use all the energy produced by the photovoltaic system to produce green hydrogen the use of a stationary energy storage device was proposed and its energy capacity was determined. The calculations contained in the article can be used to design home green hydrogen production systems and support the climate and energy transformation of small companies with a hydrogen demand of up to ¾ kg/day.
Developing Hydrogen Strategies for Fossil Fuel Exporting Countries Under Uncertainty: The Case of Qatar
Mar 2025
Publication
The economies of fossil fuel exporters are threatened by global efforts to transition away from using unabated fossil fuels. Producing clean hydrogen for export or domestic use in manufacturing provides a potentially major opportunity to continue exploiting their fossil fuel resources. However the substantial uncertainties affecting the future of clean hydrogen make developing hydrogen strategies complex. This paper characterizes such uncertainties and conducts an initial assessment of possible investment risks and critical decisions associated with different strategies in the case of Qatar a leading exporter of natural gas. We find that strategies mostly focused on using clean hydrogen domestically to produce clean commodities are relatively low risk; inversely becoming a leading exporter of clean hydrogen substantially increases investment risks. Also irrespective of the strategy higher investment is required in the early years suggesting that once a strategy is chosen changing path may prove difficult.
Technical and Economic Viability of Underground Hydrogen Storage
Nov 2023
Publication
Considering the mismatch between the renewable source availability and energy demand energy storage is increasingly vital for achieving a net-zero future. The daily/seasonal disparities produce a surplus of energy at specific moments. The question is how can this “excess” energy be stored? One promising solution is hydrogen. Conventional hydrogen storage relies on manufactured vessels. However scaling the technology requires larger volumes to satisfy peak demands enhance the reliability of renewable energies and increase hydrogen reserves for future technology and infrastructure development. The optimal solution may involve leveraging the large volumes of underground reservoirs like salt caverns and aquifers while minimizing the surface area usage and avoiding the manufacturing and safety issues inherent to traditional methods. There is a clear literature gap regarding the critical aspects of underground hydrogen storage (UHS) technology. Thus a comprehensive review of the latest developments is needed to identify these gaps and guide further R&D on the topic. This work provides a better understanding of the current situation of UHS and its future challenges. It reviews the literature published on UHS evaluates the progress in the last decades and discusses ongoing and carried-out projects suggesting that the technology is technically and economically ready for today’s needs.
Key Technologies of Pure Hydrogen and Hydrogen-mixed Natural Gas Pipeline Transportation
May 2023
Publication
Thanks to the advantages of cleanliness high efficiency extensive sources and renewable energy hydrogen energy has gradually become the focus of energy development in the world’s major economies. At present the natural gas transportation pipeline network is relatively complete while hydrogen transportation technology faces many challenges such as the lack of technical specifications high safety risks and high investment costs which are the key factors that hinder the development of hydrogen pipeline transportation. This paper provides a comprehensive overview and summary of the current status and development prospects of pure hydrogen and hydrogen-mixed natural gas pipeline transportation. Analysts believe that basic studies and case studies for hydrogen infrastructure transformation and system optimization have received extensive attention and related technical studies are mainly focused on pipeline transportation processes pipe evaluation and safe operation guarantees. There are still technical challenges in hydrogen-mixed natural gas pipelines in terms of the doping ratio and hydrogen separation and purification. To promote the industrial application of hydrogen energy it is necessary to develop more efficient low-cost and low-energy-consumption hydrogen storage materials.
Hydrogen, A Less Disruptive Pathway for Domestic Heat? Exploratory Findings from Public Perception Research
Aug 2023
Publication
The disruption associated with heat decarbonisation has been identified as a key opportunity for hydrogen technologies in temperate countries and regions where established distribution infrastructure and familiarity with natural gas boilers predominate. A key element of such claims is the empirically untested belief that citizens will prefer to minimise disruption and perceive hydrogen to be less disruptive than the network upgrades and retrofit measures needed to support electric and other low carbon heating technologies. This article reports on exploratory deliberative research with residents of Cardiff Wales which examined public perceptions of heating disruptions. Our findings suggest that concerns over public responses to disruption may be overstated particularly as they relate to construction and road excavation for network upgrade. Disruptions arising from permanent changes to building fabric may be more problematic for heat pump retrofit however these may be greatly overshadowed by anxieties over the cost implications of moving to hydrogen fuel. Furthermore the biographical patterning of citizen preferences raises significant questions for hydrogen roll-out strategies relying on regionalised network conversion. We conclude by arguing that far from a non-disruptive alternative to electrification hydrogen risks being seen as posing substantial disruptions to precarious household finances and lifestyles.
Uncertainty Quantification in Hydrogen Tank Exchange: Estimating Maintenance Costs for New Aircraft Concepts
Apr 2024
Publication
The increasing demand for sustainable air mobility has led to the development of innovative aircraft designs necessitating a balance between environmental responsibility and profitability. However despite technological advancements there is still limited understanding of the maintenance implications for hydrogen systems in aviation. The aim of this study is to estimate the maintenance costs of replacing the hydrogen storage system in an aircraft as part of its life cycle costs. To achieve this we compared conventional and hydrogenpowered aircraft. As there is insufficient data for new aircraft concepts typical probabilistic methods are not applicable. However by combining global sensitivity analysis with Dempster–Shafer Theory of Evidence and discrete event simulation it is possible to identify key uncertainties that impact maintenance costs and economic efficiency. This innovative framework offers an early estimate of maintenance costs under uncertainty enhancing understanding and assisting in decision-making when integrating hydrogen storage systems and new aviation technologies.
Comprehensive Review of Geomechanics of Underground Hydrogen Storage in Depleted Reservoirs and Salt Caverns
Sep 2023
Publication
Hydrogen is a promising energy carrier for a low-carbon future energy system as it can be stored on a megaton scale (equivalent to TWh of energy) in subsurface reservoirs. However safe and efficient underground hydrogen storage requires a thorough understanding of the geomechanics of the host rock under fluid pressure fluctuations. In this context we summarize the current state of knowledge regarding geomechanics relevant to carbon dioxide and natural gas storage in salt caverns and depleted reservoirs. We further elaborate on how this knowledge can be applied to underground hydrogen storage. The primary focus lies on the mechanical response of rocks under cyclic hydrogen injection and production fault reactivation the impact of hydrogen on rock properties and other associated risks and challenges. In addition we discuss wellbore integrity from the perspective of underground hydrogen storage. The paper provides insights into the history of energy storage laboratory scale experiments and analytical and simulation studies at the field scale. We also emphasize the current knowledge gaps and the necessity to enhance our understanding of the geomechanical aspects of hydrogen storage. This involves developing predictive models coupled with laboratory scale and field-scale testing along with benchmarking methodologies.
Comprehensive Review of Development and Applications of Hydrogen Energy Technologies in China for Carbon Neutrality: Technology Advances and Challenges
Jul 2024
Publication
Concerning the transition from a carbon-based energy economy to a renewable energy economy hydrogen is considered an essential energy carrier for efficient and broad energy systems in China in the near future. China aims to gradually replace fossil fuel-based power generation with renewable energy technologies to achieve carbon neutrality by 2060. This ambitious undertaking will involve building an industrial production chain spanning the production storage transportation and utilisation of hydrogen energy by 2030 (when China’s carbon peak will be reached). This review analyses the current status of technological R&D in China’s hydrogen energy industry. Based on published data in the open literature we compared the costs and carbon emissions for grey blue and green hydrogen production. The primary challenges concerning hydrogen transportation and storage are highlighted in this study. Given that primary carbon emissions in China are a result of power generation using fossil fuels we provide an overview of the advances in hydrogen-to-power industry technology R&D including hydrogen-related power generation technology hydrogen fuel cells hydrogen internal combustion engines hydrogen gas turbines and catalytic hydrogen combustion using liquid hydrogen carriers (e.g. ammonia methanol and ethanol).
Route-to-Market Strategy for Low-carbon Hydrogen from Natural Gas in the Permian Basin
Aug 2023
Publication
This paper investigates the untapped potential of the Permian Basin a multifaceted energy axis in Texas and adjoining states in the emerging era of decarbonization. Aligned with current policy directives on regional hydrogen hubs this study explores the viability of developing a hydrogen energy hub in the Permian Basin thereby producing low-carbon intensity hydrogen from natural gas in the Basin and transporting it to the Greater Houston area. Diverging from existing literature this study provides an integrated techno-economic evaluation of the entire hydrogen value chain in the Permian Basin encompassing production storage and transportation. Furthermore it comparatively analyzes the scenario of interest against an optimized base scenario thereby underlining comparative advantages and disadvantages. The paper concludes that the delivered cost of Permian based low-carbon intensity hydrogen to the Greater Houston area is $1.85/kg benchmarked to the scenario with hydrogen produced close to the Greater Houston area and delivered at $1.42/kg. Our findings reveal that Permian-based low-carbon intensity hydrogen production can achieve cost savings in feedstock ($0.25/kg) and potentially accrue a higher production tax credit due to a shorter gas supply chain to production ($0.33/kg). Nevertheless a significant cost barrier is the expense of long-haul pipeline transport ($0.90/kg) from the Permian Basin to Houston as opposed to local production. Despite the obstacles the study identifies a potential breakeven solution where increasing the production scale to at least 412000 metric ton per year (about 3 steam reforming plants) in the Permian Basin can effectively lower costs in the transport sector. Hence a scaled-up production can mitigate the cost difference and establish the Permian Basin as a competitive player in the hydrogen market. In conclusion a SWOT analysis presents Strengths Weaknesses Opportunities and Threats associated with Permian-based hydrogen production.
Perspective on the Development and Integration of Hydrogen Sensors for Fuel Cell Control
Oct 2024
Publication
The measurement of hydrogen concentration in fuel cell systems is an important prerequisite for the development of a control strategy to enhance system performance reduce purge losses and minimize fuel cell aging effects. In this perspective paper the working principles of hydrogen sensors are analyzed and their requirements for hydrogen control in fuel cell systems are critically discussed. The wide measurement range absence of oxygen high humidity and limited space turn out to be most limiting. A perspective on the development of hydrogen sensors based on palladium as a gas-sensitive metal and based on the organic magnetic field effect in organic lightemitting devices is presented. The design of a test chamber where the sensor response can easily be analyzed under fuel cell-like conditions is proposed. This allows the generation of practical knowledge for further sensor development. The presented sensors could be integrated into the end plate to measure the hydrogen concentration at the anode in- and outlet. Further miniaturization is necessary to integrate them into the flow field of the fuel cell to avoid fuel starvation in each single cell. Compressed sensing methods are used for more efficient data analysis. By using a dynamical sensor model control algorithms are applied with high frequency to control the hydrogen concentration the purge process and the recirculation pump.
Environmental Assessment of Replacing Fossil Fuels with Hydrogen for Motorised Equipment in the Mining Sector
Nov 2023
Publication
To achieve the European milestone of climate neutrality by 2050 the decarbonisation of energy-intensive industries is essential. In 2022 global energy-related CO2 emissions increased by 0.9% or 321 Mt reaching a peak of over 36.8 Gt. A large amount of these emissions is the result of fossil fuel usage in the motorised equipment used in mining. Heavy diesel vehicles like excavators wheel loaders and dozers are responsible for an estimated annual CO2 emissions of 400 Mt of CO2 accounting for approximately 1.1% of global CO2 emissions. In addition exhaust gases of CO2 and NOx endanger the personnel’s health in all mining operations especially in underground environments. To tackle these environmental concerns and enhance environmental health extractive industries are focusing on replacing fossil fuels with alternative fuels of low or zero CO2 emissions. In mining the International Council on Mining and Metals has committed to achieving net zero emissions by 2050 or earlier. Of the various alternative fuels hydrogen (H2 ) has seen a considerable rise in popularity in recent years as H2 combustion accounts for zero CO2 emissions due to the lack of carbon in the burning process. When combusted with pure oxygen it also accounts for zero NOx formation and near-zero emissions overall. To this end this study aims to examine the overall environmental performance of H2 -powered motorised equipment compared to conventional fossil fuel-powered equipment through Life Cycle Assessment. The assessment was conducted using the commercial software Sphera LCA for Experts following the conventionally used framework established by ISO 14040:2006 and 14044:2006/A1:2018 and the International Life Cycle Data Handbook consisting of (1) the goal and scope definition (2) the Life Cycle Inventory (LCI) preparation (3) the Life Cycle Impact Assessment (LCIA) and (4) the interpretation of the results. The results will offer an overview to support decision-makers in the sector.
A Comparative Analysis of Different Hydrogen Production Methods and Their Environmental Impact
Nov 2023
Publication
This study emphasises the growing relevance of hydrogen as a green energy source in meeting the growing need for sustainable energy solutions. It foregrounds the importance of assessing the environmental consequences of hydrogen-generating processes for their long-term viability. The article compares several hydrogen production processes in terms of scalability costeffectiveness and technical improvements. It also investigates the environmental effects of each approach considering crucial elements such as greenhouse gas emissions water use land needs and waste creation. Different industrial techniques have distinct environmental consequences. While steam methane reforming is cost-effective and has a high production capacity it is coupled with large carbon emissions. Electrolysis a technology that uses renewable resources is appealing but requires a lot of energy. Thermochemical and biomass gasification processes show promise for long-term hydrogen generation but further technological advancement is required. The research investigates techniques for improving the environmental friendliness of hydrogen generation through the use of renewable energy sources. Its ultimate purpose is to offer readers a thorough awareness of the environmental effects of various hydrogen generation strategies allowing them to make educated judgements about ecologically friendly ways. It can ease the transition to a cleaner hydrogen-powered economy by considering both technological feasibility and environmental issues enabling a more ecologically conscious and climate-friendly energy landscape.
An Assessment Methodology for International Hydrogen Competitiveness: Seven Case Studies Compared
Jun 2024
Publication
Currently the global energy structure is undergoing a transition from fossil fuels to renewable energy sources with the hydrogen economy playing a pivotal role. Hydrogen is not only an important energy carrier needed to achieve the global goal of energy conservation and emission reduction it represents a key object of the future international energy trade. As hydrogen trade expands nations are increasingly allocating resources to enhance the international competitiveness of their respective hydrogen industries. This paper introduces an index that can be used to evaluate international hydrogen competitiveness and elucidate the most competitive countries in the hydrogen trade. To calculate the competitiveness scores of seven major prospective hydrogen market participants we employed the entropy weight method. This method considers five essential factors: potential resources economic and financial base infrastructure government support and institutional environment and technological feasibility. The results indicate that the USA and Australia exhibit the highest composite indices. These findings can serve as a guide for countries in formulating suitable policies and strategies to bolster the development and international competitiveness of their respective hydrogen industries.
Different Strategies in an Integrated Thermal Management System of a Fuel Cell Electric Bus Under Real Driving Cycles in Winter
May 2023
Publication
Due to the climate crisis and the restriction measures taken in the last decade electric buses are gaining popularity in the transport sector. However one of the most significant disadvantages of this type of vehicle is its low autonomy. Many electric buses with proton-exchange membrane fuel cells (PEMFC) systems have been developed to solve this problem in recent years. These have an advantage over battery-electric buses because the autonomy depends on the capacity of the hydrogen tanks. As with batteries thermal management is crucial for fuel cells to achieve good performance and prolong service life. For this reason it is necessary to investigate different strategies or configurations of a fuel cell electric bus’s integral thermal management system (ITMS). In the present work a novel global model of a fuel cell electric bus (FCEB) has been developed which includes the thermal models of the essential components. This model was used to evaluate different strategies in the FCEB integrated thermal management system simulating driving cycles of the public transport system of Valencia Spain under winter weather conditions. The first strategy was to use the heat generated by the fuel cell to heat the vehicle’s cabin achieving savings of up to 7%. The second strategy was to use the waste heat from the fuel cells to preheat the batteries. It was found that under conditions where a high-power demand is placed on the fuel cell it is advisable to use the residual heat to preheat the battery resulting in an energy saving of 4%. Finally a hybrid solution was proposed in which the residual heat from fuel cells is used to heat both the cabin and the battery resulting in an energy saving of 10%.
Path Analysis of Using Hydrogen Energy to Reduce Greenhouse Gas Emissions in Global Aviation
Jul 2024
Publication
The rapid growth of global aviation emissions has significantly impacted the environment leading to an urgent need to use carbon reduction methods. This paper analyzes global aviation’s carbon dioxide (CO2) N2O and CH4 emission changes under different hydrogen energy application paths. The global warming potential over a 100-year period (GWP100) method is used to convert the emissions of N2O and CH4 into CO2-equivalent. Here we report the results: if the global aviation industry begins using hydrogen turbine engines by 2040 it could reduce cumulative CO2-equivalent emissions by 2.217E+10 tons by 2080 which is 2.12% higher than starting hydrogen fuel cell engines in 2045. However adopting hydrogen fuel cell engines 10 years earlier shows greater reduction capabilities than hydrogen turbine engines achieving an accumulated reduction of 3.006E+10 tons of CO2-equivalent emissions. Therefore the timing of adoption notably affects hydrogen fuel cell engines more than hydrogen turbine engines. Delaying adoption makes hydrogen fuel cell engines’ performance lag hydrogen turbine engines.
Life Cycle Analysis of Hydrogen Powered Marine Vessels—Case Ship Comparison Study with Conventional Power System
Aug 2023
Publication
The latest International Maritime Organization strategies aim to reduce 70% of the CO2 emissions and 50% of the Greenhouse Gas (GHG) emissions from maritime activities by 2050 compared to 2008 levels. The EU has set up goals to reduce GHG emissions by at least 55% by 2030 compared to 1990 and achieve net-zero GHG emissions by 2050. The UK aims to achieve more than 68% GHG emission reduction by 2030 and net-zero GHG emissions by 2050. There are many solutions under development to tackle the challenge of meeting the latest decarbonization strategies from the IMO EU and UK among which are hydrogen powered marine vessels. This paper presents a life cycle analysis study for hydrogen fuelled vessels by evaluating their performance in terms of environmental friendliness and economic feasibility. The LCA study will consider the gas emissions and costs during the life stages of the ships including the construction operation maintenance and recycling phases of the selected vessels. The results of the comparisons with the conventional version of the ships (driven by diesel generators) demonstrate the benefits of using hydrogen for marine transportation: over 80% emission reduction and around 60% life cycle cost savings. A sensitivity analysis shows that the prices of fuels and carbon credits can affect the life cycle cost and recommendations for low H2 price and high carbon credit in the future are provided to attract the industry to adopt the new fuel.
Advances in Hospital Energy Systems: Genetic Algorithm Optimization of a Hybrid Solar and Hydrogen Fuel Cell Combined Heat and Power
Sep 2024
Publication
This paper presents an innovative Fuel Cell Combined Heat and Power (FC–CHP) system designed to enhance energy efficiency in hospital settings. The system primarily utilizes solar energy captured through photovoltaic (PV) panels for electricity generation. Excess electricity is directed to an electrolyzer for water electrolysis producing hydrogen which is stored in high-pressure tanks. This hydrogen serves a dual purpose: it fuels a boiler for heating and hot water needs and powers a fuel cell for additional electricity when solar production is low. The system also features an intelligent energy management system that dynamically allocates electrical energy between immediate consumption hydrogen production and storage while also managing hydrogen release for energy production. This study focuses on optimization using genetic algorithms to optimize key components including the peak power of photovoltaic panels the nominal power of the electrolyzer fuel cell and storage tank sizes. The objective function minimizes the sum of investment and electricity costs from the grid considering a penalty coefficient. This approach ensures optimal use of renewable energy sources contributing to energy efficiency and sustainability in healthcare facilities.
Techno-economic-environmental Assessment of Green Hydrogen and Ammonia Synthesis Using Solar and Wind Resources for Three Selected Sites in Egypt
Sep 2024
Publication
The primary motivation of the present study is to mitigate the severe impact of ongoing energy resource shortages while offering clean and sustainable energy carriers such as hydrogen and ammonia. The present system mainly encompasses water splitting and the Haber-Bosch (HB) processes for green hydrogen and ammonia synthesis using solar and wind power respectively. Pointwise quantification analyses are conducted to quantify the power hydrogen and ammonia as well as the economic parameters specifically the levelized cost of energy (LCOE) levelized cost of hydrogen (LCOH) and levelized cost of ammonia (LCOA). This analysis is based on meteorological data from three sites in Egypt considering the specific water and nitrogen requirements for hydrogen and ammonia synthesis respectively. Furthermore carbon dioxide mitigation from solar and wind systems is estimated. These respective sites are Jarjoub on the coastlines of the Mediterranean Sea and Ain Sokhna and Jabal Al-Zait on the coastlines of the Red Sea. The results indicate that the lowest values of LCOE LCOH and LCOA are 12.58 $/MWh 1.91 $/kg H2 and 396.1 $/Ton NH3 respectively which were attained using solar resources at Ain Sokhna geographical site at the Red Sea. Besides Jarjoub which is located in the Mediterranean Sea could attain LCOH of 2.15 $/kg which is still a promising option due to its export potential to Europe. However the use of wind resources is incompetent for solar counterparts in the respective sites; their potential application in Egypt is still promising. The results demonstrate that Jabal Al-Zait stands as a favorable location for green power hydrogen and ammonia synthesis using wind resources which has LCOE LCOH and LCOA of 23.67 $/MWh 2.75 $/kg H2 and 547.8 $/Ton NH3 respectively.
Alternative Gaseous Fuels for Marine Vessels towards Zero-Carbon Emissions
Nov 2023
Publication
The maritime industry is recognized as a major pollution source to the environment. The use of low- or zero-carbon marine alternative fuel is a promising measure to reduce emissions of greenhouse gases and toxic pollutants leading to net-zero carbon emissions by 2050. Hydrogen (H2 ) fuel cells particularly proton exchange membrane fuel cell (PEMFC) and ammonia (NH3 ) are screened out to be the feasible marine gaseous alternative fuels. Green hydrogen can reduce the highest carbon emission which might amount to 100% among those 5 types of hydrogen. The main hurdles to the development of H2 as a marine alternative fuel include its robust and energy-consuming cryogenic storage system highly explosive characteristics economic transportation issues etc. It is anticipated that fossil fuel used for 35% of vehicles such as marine vessels automobiles or airplanes will be replaced with hydrogen fuel in Europe by 2040. Combustible NH3 can be either burned directly or blended with H2 or CH4 to form fuel mixtures. In addition ammonia is an excellent H2 carrier to facilitate its production storage transportation and usage. The replacement of promising alternative fuels can move the marine industry toward decarbonization emissions by 2050.
Optimal Planning of Renewable Energy Park for Green Hydrogen Production Using Detailed Cost and Efficiency Curves of PEM Electrolyzer
Jul 2024
Publication
Installing multi-renewable energy (RE) power plants at designated locations known as RE parks is a promising solution to address their intermittent power. This research focuses on optimizing RE parks for three scenarios: photovoltaic (PV)-only wind-only and hybrid PV-wind with the aim of generating green hydrogen in locations with different RE potentials. To ensure rapid response to RE fluctuations a Proton Exchange Membrane (PEM) electrolyzer is employed. Furthermore this research proposes detailed models for manufacturer-provided wind power curves electrolyzer efficiency against its operating power and electrolyzer cost towards its capacity. Two optimization cases are conducted in MATLAB evaluating the optimum sizes of the plants in minimizing levelized cost of hydrogen (LCOH) using classical discrete combinatorial method and determining the ideal PV-to-wind capacity ratio for operating PEM electrolyzer within hybrid PV-wind parks using particle swarm optimization. Numerical simulations show that wind power-based hydrogen production is more cost-effective than PV-only RE parks. The lowest LCOH $4.26/kg H2 and the highest LCOH $14.378/kg H2 are obtained from wind-only and PV-only configurations respectively. Both occurred in Adum-Kirkeby Denmark as it has highest average wind speed and lowest irradiance level. Notably LCOH is reduced with the hybrid PV-wind configuration. The results suggest the optimum PV-to-wind capacity ratio is 65:35 on average and indicate that LCOH is more sensitive to electrolyzer’s cost than to electricity tariff variation. This study highlights two important factors i.e. selecting the suitable location based on the available RE resources and determining the optimum size ratio between the plants within the RE park.
Optimal Sizing of Renewables-to-hydrogen Systems in a Suitable-site-selection Geospatial Framework: The Case Study if Italy and Portugal
Jun 2024
Publication
Growing renewable energy deployment worldwide has sparked a shift in the energy landscape with far-reaching geopolitical ramifications. Hydrogen’s role as an energy carrier is central to this change facilitating global trade and the decarbonisation of hard-to-abate sectors. This analysis offers a new method for optimally sizing solar/wind-to-hydrogen systems in specifically suitable locations. These locations are limited to the onshore and offshore regions of selected countries as determined by a bespoke geospatial analysis developed to be location-agnostic. Furthermore the research focuses on determining the best configurations for such systems that minimise the cost of producing hydrogen with the optimisation algorithm expanding from the detailed computation of the classic levelised cost of hydrogen. One of the study’s main conclusions is that the best hybrid configurations obtained provide up to 70% cost savings in some areas. Such findings represent unprecedented achievements for Italy and Portugal and can be a valuable asset for economic studies of this kind carried out by local and national governments across the globe. These results validate the optimisation model’s initial premise significantly improving the credibility of this work by constructively challenging the standard way of assessing large-scale green hydrogen projects.
Integration of Renewable-Energy-Based Green Hydrogen into the Energy Future
Sep 2023
Publication
There is a growing interest in green hydrogen with researchers institutions and countries focusing on its development efficiency improvement and cost reduction. This paper explores the concept of green hydrogen and its production process using renewable energy sources in several leading countries including Australia the European Union India Canada China Russia the United States South Korea South Africa Japan and other nations in North Africa. These regions possess significant potential for “green” hydrogen production supporting the transition from fossil fuels to clean energy and promoting environmental sustainability through the electrolysis process a common method of production. The paper also examines the benefits of green hydrogen as a future alternative to fossil fuels highlighting its superior environmental properties with zero net greenhouse gas emissions. Moreover it explores the potential advantages of green hydrogen utilization across various industrial commercial and transportation sectors. The research suggests that green hydrogen can be the fuel of the future when applied correctly in suitable applications with improvements in production and storage techniques as well as enhanced efficiency across multiple domains. Optimization strategies can be employed to maximize efficiency minimize costs and reduce environmental impact in the design and operation of green hydrogen production systems. International cooperation and collaborative efforts are crucial for the development of this technology and the realization of its full benefits.
A Review of Control Strategies for Proton Exchange Membrane (PEM) Fuel Cells and Water Electrolysers: From Automation to Autonomy
Jul 2024
Publication
Proton exchange membrane (PEM) based electrochemical systems have the capability to operate in fuel cell (PEMFC) and water electrolyser (PEMWE) modes enabling efficient hydrogen energy utilisation and green hydrogen production. In addition to the essential cell stacks the system of PEMFC or PEMWE consists of four sub-systems for managing gas supply power thermal and water respectively. Due to the system’s complexity even a small fluctuation in a certain sub-system can result in an unexpected response leading to a reduced performance and stability. To improve the system’s robustness and responsiveness considerable efforts have been dedicated to developing advanced control strategies. This paper comprehensively reviews various control strategies proposed in literature revealing that traditional control methods are widely employed in PEMFC and PEMWE due to their simplicity yet they suffer from limitations in accuracy. Conversely advanced control methods offer high accuracy but are hindered by poor dynamic performance. This paper highlights the recent advancements in control strategies incorporating machine learning algorithms. Additionally the paper provides a perspective on the future development of control strategies suggesting that hybrid control methods should be used for future research to leverage the strength of both sides. Notably it emphasises the role of artificial intelligence (AI) in advancing control strategies demonstrating its significant potential in facilitating the transition from automation to autonomy.
Local Energy Community to Support Hydrogen Production and Network Flexibility
Jul 2024
Publication
This paper deals with the optimal scheduling of the resources of a renewable energy community whose coordination is aimed at providing flexibility services to the electrical distribution network. The available resources are renewable generation units battery energy storage systems dispatchable loads and power-to-hydrogen systems. The main purposes behind the proposed strategy are enhancement of self-consumption and hydrogen production from local resources and the maximization of the economic benefits derived from both the selling of hydrogen and the subsidies given to the community for the shared energy. The proposed approach is formulated as an economic problem accounting for the perspectives of both community members and the distribution system operator. In more detail a mixed-integer constrained non-linear optimization problem is formulated. Technical constraints related to the resources and the power flows in the electrical grid are considered. Numerical applications allow for verifying the effectiveness of the procedure. The results show that it is possible to increase self-consumption and the production of green hydrogen while providing flexibility services through the exploitation of community resources in terms of active and reactive power support. More specifically the application of the proposed strategy to different case studies showed that daily revenues of up to EUR 1000 for each MW of renewable energy generation installed can be obtained. This value includes the benefit obtained thanks to the provision of flexibility services which contribute about 58% of the total.
Minimization of Construction and Operation Costs of the Fuel Cell Bus Transportation System
Dec 2024
Publication
This paper took the actual bus transportation system as the object simulated the operating state of the system replaced all the current diesel engine buses with fuel cell buses using electrolysis-produced hydrogen and completed the existing timetable and routes. In the study the numbers of hydrogen production stations and hydrogen storage stations the maximum hydrogen storage capacity of the buses the supplementary hydrogen capacity of the buses and the hydrogen production capacity of the hydrogen storage stations were used as the optimal adjustment parameters for minimizing the ten-year construction and operating costs of the fuel cell bus transportation system by the artificial bee colony algorithm. Two hydrogen supply methods decentralized and centralized hydrogen production were analyzed. This paper used the actual bus timetable to simulate the operation of the buses including 14 transfer stations and 112 routes. The results showed that the use of centralized hydrogen production and partitioned hydrogen production transfer stations could indeed reduce the construction and operating costs of the fuel cell bus transportation system. Compared with the decentralized hydrogen production case the construction and operating costs could be reduced by 6.9% 12.3% and 14.5% with one two and three zones for centralized hydrogen production respectively.
The Long Term Price Elastic Demand of Hydrogen - A Multi-model Analysis for Germany
May 2024
Publication
Hydrogen and its derivatives are important components to achieve climate policy goals especially in terms of greenhouse gas neutrality. There is an ongoing controversial debate about the applications in which hydrogen and its derivatives should be used and to what extent. Typically the estimation of hydrogen demand relies on scenario-based analyses with varying underlying assumptions and targets. This study establishes a new framework consisting of existing energy system simulation and optimisation models in order to assess the long-term price-elastic demand of hydrogen. The aim of this work is to shift towards an analysis of the hydrogen demand that is primarily driven by its price. This is done for the case of Germany because of the expected high hydrogen demand for the years 2025–2045. 15 wholesale price pathways were established with final prices in 2045 between 56 €/MWh and 182 €/MWh. The results suggest that – if climate targets are to be achieved - even with high hydrogen prices (252 €/MWh in 2030 and 182 €/MWh in 2045) a significant hydrogen demand in the industry sector and the energy conversion sector is expected to emerge (318 TWh). Furthermore the energy conversion sector has a large share of price sensitive hydrogen demand and therefore its demand strongly increases with lower prices. The road transportation sector will only play a small role in terms of hydrogen demand if prices are low. In the decentralised heating for buildings no relevant demand will be seen over the considered price ranges whereas the centralised supply of heat via heat grids increases as prices fall.
Renewable Electricity and Green Hydrogen Integration for Decarbonization of “Hard-to-Abate” Industrial Sectors
Jul 2024
Publication
This paper investigates hydrogen’s potential to accelerate the energy transition in hardto-abate sectors such as steel petrochemicals glass cement and paper. The goal is to assess how hydrogen produced from renewable sources can foster both industrial decarbonization and the expansion of renewable energy installations especially solar and wind. Hydrogen’s dual role as a fuel and a chemical agent for process innovation is explored with a focus on its ability to enhance energy efficiency and reduce CO2 emissions. Integrating hydrogen with continuous industrial processes minimizes the need for energy storage making it a more efficient solution. Advances in electrolysis achieving efficiencies up to 60% and storage methods consuming about 10% of stored energy for compression are discussed. Specifically in the steel sector hydrogen can replace carbon as a reductant in the direct reduced iron (DRI) process which accounts for around 7% of global steel production. A next-generation DRI plant producing one million tons of steel annually would require approximately 3200 MW of photovoltaic capacity to integrate hydrogen effectively. This study also discusses hydrogen’s role as a co-fuel in steel furnaces. Quantitative analyses show that to support typical industrial plants hydrogen facilities of several hundred to a few thousand MW are necessary. “Virtual” power plants integrating with both the electrical grid and energy-intensive systems are proposed highlighting hydrogen’s critical role in industrial decarbonization and renewable energy growth.
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